Saddle stitchers are complex machines which are composed of a plurality of individual units called pockets. These machines are produced by a number of different manufacturers such as Consolidated International Corporation in Chicago, Ill. These machines are capable of gathering and stitching anywhere from 1,000 to as many as 20,000 sheets per hour.
In recent years, artistic designers and advertisers have desired to include Z folded sheets into magazines and advertising literature. Although the incorporation of inside folded sheets into magazines does not create a serious problem in saddle stitching machines, the use of outside Z folded sheets does pose a problem. The problem relates to the inability of existing machines to feed the individual sheets through the machine without a loose edge of the sheet causing jamming of the pocket of the machine, thereby necessitating a shutdown of the entire assembly line while the pocket in which the jamming occurred is unjammed. This problem is presently addressed by feeding the sheet through the stitcher as an inside Z fold, and thereafter manually refolding the sheet to an outside fold. Obviously, this adds an expensive and time consuming manual step to the overall assembly process. Thus, there remains a serious need for remedying this problem.